Edge: U,Y,W axes don't work in probe commands (G38.x)

[prof7bit]

g38.3 u0 f100
{"er":{"fb":101.03,"st":134,"msg":"Axis word missing - Axis is missing"}

I'm trying to emulate the broken u/w/w-axis homing with a probe command. But this does not seem to be implemented. Might this be somehow related to the broken homing?

[prof7bit]

I found the reason:

The attached patch will fix both: the probing and the homing problems for U,V,W,

Please merge.

diff --git a/g2core/cycle_probing.cpp b/g2core/cycle_probing.cpp
index 3f3db80f..f8ab9423 100644
--- a/g2core/cycle_probing.cpp
+++ b/g2core/cycle_probing.cpp
@@ -138,6 +138,7 @@ uint8_t cm_straight_probe(float target[], bool flags[], bool trip_sense, bool al
 
     // error if no axes specified
     if (!(flags[AXIS_X] | flags[AXIS_Y] | flags[AXIS_Z] |
+          flags[AXIS_U] | flags[AXIS_V] | flags[AXIS_W] |
           flags[AXIS_A] | flags[AXIS_B] | flags[AXIS_C])) {
         return(cm_alarm(STAT_AXIS_IS_MISSING, "Axis is missing"));
     }
diff --git a/g2core/util.cpp b/g2core/util.cpp
index 61f4c4b0..952bb0fe 100644
--- a/g2core/util.cpp
+++ b/g2core/util.cpp
@@ -76,6 +76,9 @@ float get_axis_vector_length(const float a[], const float b[])
     return (sqrt(square(a[AXIS_X] - b[AXIS_X]) +
                  square(a[AXIS_Y] - b[AXIS_Y]) +
                  square(a[AXIS_Z] - b[AXIS_Z]) +
+                 square(a[AXIS_U] - b[AXIS_U]) +
+                 square(a[AXIS_V] - b[AXIS_V]) +
+                 square(a[AXIS_W] - b[AXIS_W]) +
                  square(a[AXIS_A] - b[AXIS_A]) +
                  square(a[AXIS_B] - b[AXIS_B]) +
                  square(a[AXIS_C] - b[AXIS_C])));